Is it okay if I use whey protein?

Hello everyone, I'm 13, almost 14 (in June) and I lift weights, and do parkour. I need to gain muscle and strength. Right now, I'm 5'6 and 140lbs, my friend is the same height bt weighs about 29lbs less. Most of my friends the same height weigh less than bt Im thinking my "extra weight" is from muscle. Bt anyways, back to the point. I was wondering if its okay for a 13/14 year old to use whey protein. Please answer back, it would be great if any fitness/weight trainers would question!